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ARS Home » Research » Publications at this Location » Publication #62319
Title: THE CHORIONIC MORPHOLOGY OF EGGS OF THE PSOROPHORA CONFINNIS COMPLEX IN THEUNITED STATES. II. PREDEPOSITION AND POST-DEPOSITION STUDIES OF PSOROPHORACOLUMBIAE (DYAR AND KNAB) EGGS

Author
item BOSWORTH, A - RETIRED/U.S. ARMY
item Meola, Shirlee
item THOMPSON, JONATHAN - RETIRED/USDA-ARS-FAPRL
item OLSON, JIM - TEXAS A&M UNIVERSITY

Submitted to: Systematic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: The group of mosquitoes known as the Psorophora confinnis complex is one of the most prolific that breeds in the rice paddies of south Texas. They are fierce biters and large swarms are noted for harassing livestock to exhaustion, reducing milk production, and reducing feed utilization efficiency. Psorophora mosquitoes have also been shown to be carriers of two important animal diseases, equine encephalitis and dengue fever. For this reason, research on how these insects develop is important. Using highly sophisticated photography techniques (scanning and transmission electron microscopy), we determined how certain markings on the eggs of these insects are formed. This information will be useful in field studies to better understand these important insects and to monitor their presence in the environment where they occur.

Technical Abstract: Detailed scanning and transmission electron microscopic studies were done on eggs of Psorophora columbiae (Dyar and Knab), a member of the Psorophora confinnis complex. In pre-deposited eggs, the outer chorion is located directly beneath the follicular epithelium and appears as a network of small, widely marginated/polygonal cells. The structure of the outer chorionic tubercles and reticulations appear to be the follicular epithelium. Post-deposited eggs increase in size once they are deposited. Major outer chorionic tubercles appear to have three distinct regions, and give these eggs a spiny appearance.